Polymeric organosilicon compounds, their production and use

ABSTRACT

The invention relates to novel polymeric organosilicon compounds comprising hydrocarbon radicals with at least one aliphatic carbon-carbon double bond in a terminal position. To produce these compounds, (A) compounds containing at least one aliphatic carbon-carbon double bond per molecule, in a terminal position, are reacted with (B) oligomeric or polymeric organosilicon compounds containing units of the general formula R 1 R 2 SiO 1/2  and units of the general formula HRSiO and/or HSiO 3/2  and possibly units of the general formula R 2 SiO, where R is a monovalent, possibly substituted, hydrocarbon radical with between 1 and 18 carbon atoms per radical, which is free of aliphatic carbon-carbon double bonds, and R 1  is a monovalent hydrocarbon radical with between 1 and 18 carbon atoms per radical which has at least one aliphatic carbon-carbon double bond in a terminal position, subject to the condition that the sum of the units HRSiO and R 1 R 2 SiO 1/2  on average is greater than 2.0 if (B) contains no HSiO 3/2  units, and the number of R 1  radicals per molecule is greater than the number of Si-bonded hydrogen atoms, in the presence of (C) catalysts promoting the addition of Si-bonded hydrogen to aliphatic double-bonds. The ratio of aliphatic double bonds in components (A) and (B) to Si-bonded hydrogen in component (B) is between 1.5 and 10, subject to the condition that the polymeric organosilicon compounds on average contain more than two hydrocarbon radicals with at least one aliphatic carbon-carbon double bond in a terminal position.

The invention relates to polymeric organosilicon compounds which containhydrocarbon radicals having terminal aliphatic carbon-carbon doublebonds, to a process for their preparation, and to their use incrosslinkable compositions, in particular for preparing antiadhesivecoatings.

Polyaddition reactions of organopolysiloxanes having at least threeSi-bonded hydrogen atoms per molecule withα,ω-dialkenyldiorganopolysiloxanes lead, with a C═C/Si—H ratio of closeto 1, to insoluble networks. If soluble alkenyl-containingorganopolysiloxanes are to be prepared, a larger excess of theα,ω-dialkenyldiorganopolysiloxane is necessary, which after the end ofthe polyaddition cannot be removed and thus dilutes the polyadditionproduct.

U.S. Pat. No. 5,241,034 discloses alkenyl-containing siloxane copolymerswhich are prepared by reacting an organic compound (1) having two, threeor four terminal aliphatic carbon-carbon double bonds with anorganopolysiloxane (2) which contains Si-bonded hydrogen atoms in thepresence of a hydrosilylation catalyst. In this reaction, polyadditionproducts are obtained in which organopolysiloxane blocks are connectedby hydrocarbon bridges. In order to obtain unsaturated siloxanecopolymers the ratio of C═C double bond in organic compound (1) toSi-bonded hydrogen in the organopolysiloxane (2) must always be greaterthan 1. The organopolysiloxane (2) containing Si-bonded hydrogen atomsdoes not contain any alkenyl radicals.

U.S. Pat. No. 5,504,175 describes a process for preparing linearα,ω-dialkenyldiorganopolysiloxanes in which a linearα-hydrido-ω-alkenyldiorganopolysiloxane is reacted with a linearα,ω-dialkenyldiorganosiloxane in the presence of a hydrosilylationcatalyst. The linear α,ω-dialkenyldiorganopolysiloxanes prepared by theprocess can contain on average not more than two alkenyl groups.

In J. Inorg. Organomet. Polymer 4 (1), 61 (1994) a process is describedfor preparing highly branched vinylsiloxanes. A platinum catalyst isadded to tris(dimethylvinylsiloxy)silane, and the system reacts in anuncontrollable polyaddition to give siloxanes with a high vinyl density.Tris(dimethylvinylsiloxy)silane contains three vinyl groups and oneSi-bonded hydrogen atom per molecule. Compounds which contain alkenylgroups and are free from Si-bonded hydrogen are not employed in theprocess.

The object was to provide polymeric organosilicon compounds which arebranched or star-shaped, which contain on average more than twohydrocarbon radicals having at least one terminal aliphaticcarbon-carbon double bond, which contain only small amounts of linearα,ω-dialkenyldiorganopolysiloxanes, which can be prepared by a simpleprocess, and which crosslink with organosilicon compounds containingSi-bonded hydrogen atoms in the presence of catalysts which promote theaddition of Si-bonded hydrogen onto aliphatic multiple bond. The objectwas, furthermore, to provide crosslinkable compositions which aresuitable for preparing coatings which repel tacky substances. The objectis achieved by the invention.

The invention provides polymeric organosilicon compounds which containhydrocarbon radicals having at least one terminal aliphaticcarbon-carbon double bond, preparable by reacting

(A) compounds which contain at least one terminal aliphaticcarbon-carbon double bond per molecule with

(B) oligomeric or polymeric organosilicon compounds which comprise unitsof the general formula

R¹R₂SiO_(1/2)

and units of the general formula

HRSiO and/or HSiO_(3/2)

and, if desired, units of the general formula

R₂SiO,

where R is identical or different at each occurrence and is amonovalent, substituted or unsubstituted hydrocarbon radical having 1 to18 carbon atoms per radical, which is free from aliphatic carbon-carbondouble bonds,

R¹ is identical or different at each occurrence and is a monovalenthydrocarbon radical having 1 to 18 carbon atoms per radical, whichcontains at least one terminal aliphatic carbon-carbon double bond,

with the proviso that the sum of the units HRSiO and R¹R₂SiO_(1/2) is onaverage greater than 2.0 if (B) contains no units HSiO_(3/2), and thenumber of radicals R¹ is on average greater than the number of Si-bondedhydrogen atoms, in the presence of

(C) catalysts which promote the addition of Si-bonded hydrogen ontoaliphatic double bond,

the ratio of aliphatic double bond in components (A) and (B) toSi-bonded hydrogen in component (B) that is employed being from 1.5 to10, preferably from 1.5 to 5.0, more preferably from 1.5 to 4.0,

with the proviso that the polymeric organosilicon compounds contain onaverage more than two hydrocarbon radicals having at least one terminalaliphatic carbon-carbon double bond.

The invention also provides a process for preparing polymericorganosilicon compounds which contain hydrocarbon radicals having atleast one terminal aliphatic carbon-carbon double bond, which comprisesreacting

(A) compounds which contain at least one terminal aliphaticcarbon-carbon double bond per molecule with

(B) oligomeric or polymeric organosilicon compounds which comprise unitsof the general formula

 R¹R₂SiO_(1/2)

and units of the general formula

HRSiO and/or HSiO_(3/2)

and, if desired, units of the general formula R₂SiO,

where R and R¹ are as defined above, with the proviso that the sum ofthe units HRSiO and R¹R₂SiO_(1/2) is on average greater than 2.0 if (B)contains no units HSiO_(3/2), and the number of radicals R¹ is onaverage greater than the number of Si-bonded hydrogen atoms, in thepresence of

(C) catalysts which promote the addition of Si-bonded hydrogen ontoaliphatic double bond,

the ratio of aliphatic double bond in components (A) and (B) toSi-bonded hydrogen in component (B) that is employed being from 1.5 to10, preferably from 1.5 to 5.0, more preferably from 1.5 to 4.0,

with the proviso that the resulting polymeric organosilicon compoundscontain on average more than two hydrocarbon radicals having at leastone terminal aliphatic carbon-carbon double bond.

The polymeric organosilicon compounds of the invention preferably have aviscosity of from 20 to 2,000,000 mPa.s at 25° C., preferably from 100to 500,000 mPa.s at 25° C.

Preferably, the numerical content of hydrocarbon radicals having atleast one terminal aliphatic carbon-carbon double bond in the polymericorganosilicon compounds of the invention is such that they contain onaverage from 2.5 to 50 terminal aliphatic carbon-carbon double bonds.

The polymeric organosilicon compounds of the invention preferably haveiodine numbers of from 0.5 to 40, preferably from 1.0 to 20, the iodinenumber indicating the amount of iodine, in grams, consumed in the courseof addition onto the double bond, per 100 grams of organopolysiloxane ofthe invention that is employed.

In the process of the invention it is preferred to employ as component(A) polymeric organosilicon compounds selected from the group of thegeneral formula

R¹ _(a)R_(3−a)Si(R¹RSi)_(n)(R₂Si)_(m)SiR¹ _(a)R_(3−a)  (I)

R¹ _(a)R_(3−a)SiO(R¹RSiO)_(n)(R₂SiO)_(m)SiR¹ _(a)R_(3−a)  (II)

and

R¹ _(a)R_(3−a)Si—R²—(R¹RSi—R²—)_(n)(R₂Si—R²—)_(m)SiR¹_(a)R_(3−a)  (III),

preferably organopolysiloxanes of the general formula

R¹ _(a)R_(3−a)SiO(R¹RSiO)_(n)(R₂SiO)_(m)SiR¹ _(a)R_(3−a)  (II)

where R and R¹ are as defined above,

R² is a divalent hydrocarbon radical having 2 to 8 carbon atoms,

a is identical or different at each occurrence and is 0 or 1, preferably1,

n is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and

m is 0 or an integer from 1 to 1500,

with the proviso that they contain at least one terminal radical R¹ permolecule.

The organosilicon compounds of the formula (I), (II) or (III) which areemployed as component (A) can also comprise, to a minor extent,preferably less than 5 mol-%, T or Q units, and also bifunctionalbridges or trifunctional organic branching sites.

The organopolysiloxanes of the formula (II) preferably have a viscosityof from 1 to 100,000 mm²/s at 25° C.

Processes for preparing the organopolysiloxanes of the formula (II) areknown to the skilled worker.

Examples of the radical R are alkyl radicals, such as the methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl,neopentyl and the tert-pentyl radical, hexyl radicals, such as then-hexyl radical, heptyl radicals, such as the n-heptyl radical, octylradicals, such as the n-octyl radical and isooctyl radicals, such as the2,2,4-trimethylpentyl and the 2-ethylhexyl radical, nonyl radicals, suchas the n-nonyl radical, decyl radicals, such as the n-decyl radical,dodecyl radicals, such as the n-dodecyl radical, tetradecyl radicals,such as the n-tetradecyl radical, hexadecyl radicals, such as then-hexadecyl radical, and octadecyl radicals, such as the n-octadecylradical, cycloalkyl radicals, such as cyclopentyl, cyclohexyl and4-ethylcyclohexyl radical, cycloheptyl radicals, norbornyl radicals andmethylcyclohexyl radicals, aryl radicals, such as the phenyl,biphenylyl, naphthyl and anthryl and phenanthryl radical; alkarylradicals, such as o-, m-, p-tolyl radicals, xylyl radicals andethylphenyl radicals; aralkyl radicals, such as the benzyl radical, andthe α- and the β-phenylethyl radicals.

The radical R is preferably the methyl radical.

Examples of substituted radicals R are halogenated radicals and radicalsinterrupted by one or more ether oxygen atoms.

Examples of halogenated radicals R are haloalkyl radicals, such as the3,3,3-trifluoro-n-propyl radical, the 2,2,2,2′,2′,2′-hexafluoroisopropylradical, the heptafluoroisopropyl radical and haloaryl radicals, such asthe o-, m- and p-chlorophenyl radical.

Examples of substituted radicals R are radicals interrupted by one ormore ether oxygen atoms, such as the 2-methoxyethyl and the2-ethoxyethyl radical.

Examples of radicals R¹ are the vinyl, allyl, 3-butenyl, 5-hexenyl,7-octenyl, 9-decenyl and the 11-dodecenyl radical, preference beinggiven to the vinyl and the 5-hexenyl radical and particular preferenceto the vinyl radical.

Examples of radicals R² are those of the formula —CH₂CH₂—, —CH(CH₃)—,—(CH₂)₄—, —(CH₂)₅—, —(CH₂)₆—, —(CH₂)₈—, —(CH₂)₁₀—, —(CH₂)₁₂—, preferencebeing given to the radicals of the formula —CH₂CH₂—, —CH(CH₃)—,—(CH₂)₆—, —(CH₂)₈— and particular preference to the radical of theformula —CH₂CH₂—.

In the process of the invention it is possible as component (A) toemploy organic compounds of the general formula

Y(CH═CH₂)_(x)  (IV)

where Y is a mono-, di-, tri- or tetravalent, preferably a divalent ortrivalent, hydrocarbon radical having 1 to 28 carbon atoms, which can beinterrupted by one or more oxygen, silicon, boron or titanium atoms orcontains one or more —CO₂ groups, and

x is 1, 2, 3 or 4, preferably 2 or 3.

Examples of x=1 are 1-pentene, 1-hexene, 1-octene, 1-dodecene,1-tetradecene and 1-octadecene, and also ethylene glycol allyl methylether, allyl propyl ether, vinyl butyl ether and butyl 5-hexenyl ether,and also trimethylvinylsilane, tributylvinyltitanium, allyl acetate,dimethylvinylbutoxysilane, diethylvinylmethoxysilane andtriethoxyvinylsilane.

Examples of x=2 are 1,5-hexadiene, 1,7-octadiene, diallyl ether,didodecenyl ether, divinyldimethylsilane, butyldiallylboron, vinylundecenoate and diallyl adipate.

Examples of x=3 are 1,2,4-trivinylcyclohexane,3,5-dimethyl-4-vinyl-1,6-heptadiene, pentaerythritol triallyl ether,methyltrivinylsilane, triallylboron and triallyl benzenetricarboxylate.

Examples of x=4 are tetravinylcyclobutane and tetravinylsilane.

Component (B) preferably comprises units of the general formula HRSiO,R¹R₂SiO_(1/2) and, if desired, R₂SiO, where R and R¹ are as definedabove. If component (B) comprises units of the formula HSiO_(3/2), whichis not preferred, branching is already present.

In the process of the invention it is preferred as component (B) toemploy organopolysiloxanes of the general formula

(R¹_(b)R_(3−b)SiO_(1/2))_(2+r)(R¹RSiO)_(o)(HRSiO)_(p)(R₂SiO)_(q)(HSiO_(3/2))r  (V)

where R and R¹ are as defined above,

b is identical or different at each occurrence and is 0 or 1, especially1

o is 0, 1, 2 or 3, especially 0 or 1,

p is 1, 2 or 3, especially 1 or 2,

q is 0 or an integer from 1 to 100, in particular from 10 to 80, and ris 0, 1 or 2, especially 0 or 1,

with the proviso that the sum b+p is on average greater than 2.0, if ris 0, and the number of radicals R¹ is on average greater than thenumber of Si-bonded hydrogen atoms.

In the process of the invention it is particularly preferred ascomponent (B) to employ organopolysiloxanes of the general formula

R¹ _(b)R_(3−b)SiO(R¹RSiO)_(o)(HRSiO)_(p)(R₂SiO)_(q)SiR¹_(b)R_(3−b)  (VI)

where R and R¹ are as defined above,

b is identical or different at each occurrence and is 0 or 1, especially1

o is 0, 1, 2 or 3, especially 0 or 1,

p is 1, 2 or 3, especially 1 or 2,

q is 0 or an integer from 1 to 100, in particular from 10 to 80,

with the proviso that the sum b+p is on average greater than 2.0, andthe number of radicals R¹ is on average greater than the number ofSi-bonded hydrogen atoms.

The organopolysiloxanes employed as component (B) preferably contain 1to 4 radicals R¹, more preferably on average from 1.5 to 3.0 radicalsR¹, and preferably on average from 0.8 to 1.5 Si-bonded hydrogen atoms.

Component (B) preferably contains on average at least 1.3, morepreferably on average at least 1.5 times as many radicals R¹ asSi-bonded hydrogen atoms.

Component (B) preferably has a viscosity of from 5 to 150 mm²/s at 25°C.

Organopolysiloxanes of the formula (V) are prepared by equilibratingorganopolysiloxanes having terminal units of the formula R¹R₂SiO_(1/2)and, if desired, R₃SiO_(1/2) with organopolysiloxanes having Si-bondedhydrogen atoms in HRSiO and/or HSiO_(3/2) units, where R and R¹ are asdefined above.

As catalysts (C) which promote the addition of Si-bonded hydrogen ontoaliphatic double bond it is also possible in the process of theinvention to employ the same catalysts which it has also been possibleto employ to date to promote the addition of Si-bonded hydrogen ontoaliphatic double bond. The catalysts (C) preferably comprise a metalfrom the group of the platinum metals, or a compound or a complex fromthe group of the platinum metals. Examples of such catalysts aremetallic and finely divided platinum, which can be on carriers such assilica, alumina or active charcoal, compounds or complexes of platinum,such as platinum halides, for example PtCl₄, H₂PtCl₆*6H₂O,Na₂PtCl₄*4H₂O, platinum-olefin complexes, platinum-alcohol complexes,platinum-alcoholate complexes, platinum-ether complexes,platinum-aldehyde complexes, platinum-ketone complexes, includingreaction products of H₂PtCl₆*6H₂O and cyclohexanone,platinum-vinylsiloxane complexes, such asplatinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes with orwithout a content of detectable inorganically bonded halogen,bis(gamma-picoline)platinum dichloride, trimethylenedipyridineplatinumdichloride, dicyclopentadieneplatinum dichloride, dimethylsulfoxide-ethyleneplatinum(II) dichloride, cycloctadieneplatinumdichloride, norbornadieneplatinum dichloride, gamma-picolineplatinumdichloride, cyclopentadieneplatinum dichloride, and reaction products ofplatinum tetrachloride with olefin and primary amine or secondary amineor primary and secondary amine in accordance with U.S. Pat. No.4,292,434, such as the reaction product of platinum tetrachloridedissolved in 1-octene with sec-butylamine, or ammonium-platinumcomplexes according to EP-B 110 370.

The catalyst (C) is preferably used in amounts of from 1 to 100 ppm byweight (parts by weight per million parts by weight), more preferably inamounts of from 4 to 20 ppm by weight, calculated in each case aselemental platinum and based on the overall weight of components (A) and(B).

The process of the invention is preferably conducted at the pressure ofthe surrounding atmosphere, i.e. at about 1020 hPa (abs.), but can alsobe conducted at higher or lower pressures. Furthermore, the process ofthe invention is preferably conducted at a temperature of from 50° C. to150° C., more preferably from 60° C. to 120° C.

In the process of the invention it is also possible to use inert organicsolvents, although the use of inert organic solvents is not preferred.Examples of inert organic solvents are toluene, xylene, octane isomers,butyl acetate, 1,2-dimethoxyethane, tetrahydrofuran and cyclohexane.

The inert organic solvents, if used, are subsequently removed bydistillation. High-polymer products preferably remain in solution in theinert solvent.

A preferred variant of the preparation process is the metered additionof component (B) to a solution of the catalyst (C) in component (A) at atemperature of from 40 to 120° C., or, if solvents are used, in atemperature range below their boiling points.

A further preferred variant is the mixing of components (A) and (B),with or without the use of solvents, with subsequent addition of acatalyst (C), after which the homogeneous mixture is heated to reactiontemperature.

The process of the invention can be carried out batchwise,semicontinuously or fully continuously.

The polymeric organosilicon compounds of the invention can becrosslinked with organopolysiloxanes containing Si-bonded hydrogen atomsin the presence of hydrosilylation catalysts. In addition, the polymericorganosilicon compounds of the invention can also be crosslinked withorganic polymers containing mercapto groups.

The polymeric organosilicon compounds of the invention are preferablyused in crosslinkable compositions comprising

(1) polymeric organosilicon compounds of the invention, or the polymericorganosilicon compounds prepared by the process of the invention,

(2) organosilicon compounds containing Si-bonded hydrogen atoms,

(3) catalysts which promote the addition of Si-bonded hydrogen ontoaliphatic multiple bond

and, if desired,

(4) agents which retard the addition of Si-bonded hydrogen ontoaliphatic multiple bond at room temperature.

The crosslinkable compositions comprising the polymeric organosiliconcompounds of the invention are preferably used for preparing coatingswhich repel tacky substances, for example for producing release papers.

The self-adhesive materials joined to the release paper are prepared bythe off-line method or the in-line method. In the off-line method, thesilicone composition is applied to the paper and crosslinked and then,in a subsequent step, normally after the winding up of the release paperonto a roll and after storage of the roll, an adhesive film, which liesfor example on a label face paper, is applied to the coated paper andthe assembly is then pressed together. In the in-line method, thesilicone composition is applied to the paper and crosslinked, thesilicone coating is coated with the adhesive, the label face paper isthen applied to the adhesive, and finally the assembly is pressedtogether.

In connection with the compositions of the invention it is possible toemploy one kind of polymeric organosilicon compound (1) or differentkinds of polymeric organosilicon compounds (1).

In the case of solvent-free compositions the polymeric organosiliconcompounds (1) preferably contain from 2.5 to 6, with particularpreference from 2.5 to 5 terminal aliphatic carbon-carbon double bonds.

In the case of solvent-containing compositions the polymericorganosilicon compounds (1) preferably contain from 5 to 50, withparticular preference from 8 to 40 terminal aliphatic carbon-carbondouble bonds.

As constituent (2) it is also possible with the compositions of theinvention to use the same organosilicon compounds, containing Si-bondedhydrogen atoms, which it has been possible to employ in connection withall hitherto known compositions comprising organosilicon compoundscontaining aliphatically unsaturated hydrocarbon radicals, such as vinylgroups, organosilicon compounds containing Si-bonded hydrogen atoms, andcatalysts which promote the addition of Si-bonded hydrogen ontoaliphatic multiple bond.

As constituent (2) it is preferred to use organopolysiloxanes comprisingunits of the formula $H_{e}R_{f}{SiO}_{\frac{4 - {({e + f})}}{2}}$

where R is as defined above,

e is 0 or 1,

f is 0, 1, 2 or 3, and

the sum e+f is not greater than 3,

more preferably those of the formula

H_(g)R_(3−g)SiO(SiR₂O)_(k)(SiRHO)₁SiR_(3−g)H_(g)

where R is as defined above,

g is 0 or 1,

k is 0 or an integer from 1 to 100, and

1 is 0 or an integer from 1 to 100, or organosilicon compoundscontaining Si-bonded hydrogen atoms as are described in the Germanapplication with the file reference 196 02 663.6, to the Applicant, ormixtures of the abovementioned organopolysiloxanes and organosiliconcompounds.

The organopolysiloxanes (2) preferably contain at least 3 Si-bondedhydrogen atoms.

Examples of organopolysiloxanes (2) are, in particular, copolymers ofdimethylhydridosiloxane, methylhydridosiloxane, dimethylsiloxane andtrimethylsiloxane units, copolymers of trimethylsiloxane,dimethylhydridosiloxane and methylhydridosiloxane units, copolymers oftrimethylsiloxane, dimethylsiloxane and methylhydridosiloxane units,copolymers of methylhydridosiloxane and trimethylsiloxane units,copolymers of methylhydridosiloxane, diphenylsiloxane andtrimethylsiloxane units, copolymers of methylhydridosiloxane,dimethylhydridosiloxane and diphenylsiloxane units, copolymers ofmethylhydridosiloxane, phenylmethylsiloxane, trimethylsiloxane and/ordimethylhydridosiloxane units, copolymers of methylhydridosiloxane,dimethylsiloxane, diphenylsiloxane, trimethylsiloxane and/ordimethylhydridosiloxane units, and also copolymers ofdimethylhydridosiloxane, trimethylsiloxane, phenylhydridosiloxane,dimethylsiloxane and/or phenylmethylsiloxane units.

Processes for preparing organosilicon compounds (2), including thoseorganopolysiloxanes (2) of the preferred type, are general knowledge.

Organosilicon compounds (2) are preferably employed in amounts of from0.5 to 6, more preferably from 1 to 3 and, with particular preference,from 1.5 to 2.5 gram atoms of Si-bonded hydrogen per mole of radical R¹in the polymeric organosilicon compounds (1).

As catalysts (3) which promote the addition of Si-bonded hydrogen ontoaliphatic multiple bond, with the compositions of the invention as wellit is possible to use the same catalysts which it has also been possibleto employ to promote crosslinking in the case of the compositions knownto date for crosslinking organosilicon compounds containing aliphaticmultiple bonds with compounds which contain Si-bonded hydrogen. Asconstituent (3) it is preferred to use the abovementioned catalysts (C).

Catalyst (3) is preferably employed in amounts of from 5 to 500 ppm byweight (parts by weight per million parts by weight), in particular from10 to 200 ppm by weight, calculated in each case as elemental platinummetal and based on the overall weight of the organopolysiloxanes (1) and(2).

As agents which retard the addition of Si-bonded hydrogen onto aliphaticmultiple bond at room temperature, so-called inhibitors (4), it is alsopossible with the compositions of the invention to use, if desired, allinhibitors which it has been possible to use to date for the samepurpose. Examples of inhibitors are1,3-divinyl-1,1,3,3-tetramethyldisiloxane, benzotriazole,dialkylformamide, alkylthioureas, methyl ethyl ketoxime, organic ororganosilicon compounds having a boiling point of at least 25° C. at1012 mbar (abs.) and at least one aliphatic triple bond, in accordancewith U.S. Pat. No. 3,445,420, such as 1-ethynylcyclohexan-1-ol,2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol,2,5-dimethyl-3-hexyn-2,5-diol and 3,5-dimethyl-1-hexyn-3-ol,3,7-dimethyloct-1-yn-6-en-3-ol, inhibitors according to U.S. Pat. No.2,476,166, such as a mixture of diallyl maleate and vinyl acetate, andinhibitors according to U.S. Pat. No. 4,504,645, such as maleicmonoesters.

The inhibitor (4) is preferably employed in amounts of from 0.001 to 10%by weight, based on the overall weight of the organopolysiloxanes (1)and (2).

Examples of further constituents which can also be used in thecompositions of the invention are agents for adjusting the releaseforce, solvents, adhesion promoters and pigments.

Examples of agents for adjusting the release force of the coatingsprepared with the compositions of the invention, which coatings repeltacky substances, are silicone resins comprising units of the formula

 R³(CH₃)₂SiO_(1/2) and SiO₂,

so-called MQ resins, where R³ is a hydrogen atom, a methyl radical or R¹and the units of the formula R³(CH₃)₂SiO_(1/2) can be identical ordifferent. The ratio of units of the formula R³(CH₃)₂SiO_(1/2) to unitsof the formula SiO₂ is preferably from 0.6 to 2. The silicone resins arepreferably employed in amounts of from 5 to 80% by weight, based on theoverall weight of the organopolysiloxanes (1) and (2).

The solvents which may be used in connection with the compositions ofthe invention can be the same solvents which it has been possible to usein the compositions known to date comprising organopolysiloxanescontaining aliphatically unsaturated hydrocarbon radicals,organopolysiloxanes containing Si-bonded hydrogen, and catalysts whichpromote the addition of Si-bonded hydrogen onto aliphatic double bonds.Examples of such solvents are benzines, for example alkane mixtureshaving a boiling range of 80° C. to 110° C. at 1012 mbar (abs.),n-heptane, benzene, toluene and xylenes, halogenated alkanes having 1 to6 carbon atoms, such as methylene chloride, trichloroethylene andperchloroethylene, ethers, such as di-n-butyl ether, esters, such asethyl acetate, and ketones, such as methyl ethyl ketone andcyclohexanone.

If organic solvents are used they are judiciously employed in amounts offrom 10 to 95% by weight, based on the weight of the polymericorganosilicone compounds (1).

The sequence when mixing the constituents (1) (2), (3) and, if used, (4)is not in fact critical; for practical purposes it has been foundappropriate, however, to add the constituent (3), i.e. the catalyst,last to the mixture of the other constituents.

The crosslinking of the compositions of the invention takes placepreferably at from 50° C. to 150° C. An advantage with the compositionsof the invention is that rapid crosslinking is achieved even at lowtemperatures. Energy sources used for crosslinking by heating arepreferably ovens, for example convection drying ovens, heating passages,heated rollers, heated plates or heat rays from the infra-red range.

Apart from by heating the compositions of the invention can also becrosslinked by irradiation with ultraviolet light or by irradiation withUV and IR light. The ultraviolet light used is customarily that with awavelength of 253.7 nm. In commerce there are a large number of lampswhich emit ultraviolet light with a wavelength of from 200 to 400 nm,and which preferentially emit ultraviolet light with a wavelength of253.7 nm.

The application of the compositions of the invention to the surfaces tobe made repellent to tacky substances can be accomplished in any desiredmanner which is suitable and widely known for the preparation ofcoatings from liquid substances, for example by dipping, brushing,pouring, spraying, rolling, printing, for example by means of an offsetgravure coating device, by knife coating, or by means of an airbrush.

The surfaces to be made repellent to tacky substances and which can betreated in the context of the invention can comprise surfaces of anydesired materials which are solid at room temperature and 1012 mbar(abs.). Examples of such surfaces are those of paper, wood, cork andpolymer films, for example polyethylene films or polypropylene films,woven and nonwoven fabric of natural or synthetic fibers or glassfibers, ceramic articles, glass, metals, polyethylene-coated paper, andboards, including that of asbestos. The abovementioned polyethylene canin each case comprise high-pressure, medium-pressure or low-pressurepolyethylene. The paper can comprise low-grade paper types, such asabsorbent papers, including kraft paper which is raw, i.e. has not beenpretreated with chemicals and/or polymeric natural substances, having aweight of from 60 to 150 g/m², unsized papers, papers of low freenessvalue, mechanical papers, unglazed or uncalendered papers, papers whichare smooth on one side owing to the use of a dry glazing cylinder duringtheir production, without additional complex measures, and are thereforereferred to as “machine-glazed papers”, uncoated papers or papersproduced from waste paper, i.e. so-called recycled papers. The paper tobe treated in accordance with the invention can also, however, of coursecomprise high-grade papers, such as low-absorbency papers, sized papers,papers of high freeness value, chemical papers, calendered or glazedpapers, glassine papers, parchmentized papers or precoated papers. Theboards may also be of low or high grade.

The compositions of the invention are suitable, for example, for theproduction of release, backing and interleaving papers, includinginterleaving papers which are employed in the production of, forexample, cast films or decorative films, or of foams, including those ofpolyurethane. The compositions of the invention are also suitable, forexample, for the production of release, backing and interleaving cards,films and cloths, for treating the reverse sides of self-adhesive tapesor self-adhesive films or the written faces of self-adhesive labels. Thecompositions of the invention are additionally suitable for treatingpackaging material, such as that comprising paper, cardboard boxes,metal foils and drums, for example, cardboard, plastic, wood or iron,which is or are intended for the storage and/or transportation of tackygoods, such as adhesives, sticky foodstuffs, for example cakes, honey,candies and meat, bitumen, asphalt, greased materials and crude rubber.A further example of the use of the compositions of the invention is thetreatment of supports for the transfer of pressure-sensitive adhesivelayers in the so-called transfer process.

The compositions of the invention are also suitable for the productionof the self-adhesive materials joined to the release paper, both by theoff-line method and by the in-line method.

Preparing Component (B)

a) Component B-1

1167 g of an equilibrate comprising dimethylsiloxy andvinyldimethylsiloxy units, with an iodine number of 22, together with32.5 g of a hydrolysate of hydridomethyldichlorosilane which isterminated with trimethylsiloxy units and has a chain length of about 40Si units, are equilibrated at 145° C. with 100 ppm of PNCl₂. Thecatalyst is deactivated by MgO and volatile constituents are removed at140° C. and 3 hPa. This gives a polysiloxane having on average 1.9vinyldimethylsiloxy and 1.1 hydridomethylsiloxy units per molecule and aviscosity of 32 mm²/s at 25° C.

b) Component B-2

The following siloxanes are equilibrated at 145° C. with 75 ppm ofPNCl₂:

1400 g of a trimethylsiloxy-terminated dimethylpolysiloxane having aviscosity of 10,000 mm²/s at 25° C., 100 g ofdivinyltetramethyldisiloxane, and

80 g of a trimethylsiloxy-terminated equilibrate comprising equimolaramounts of dimethylsiloxy and hydridomethylsiloxy units, having aviscosity of 70 mm²/s at 25° C.

The product is worked up in accordance with the preparation of componentB-1. This gives a polymer with Si-bonded vinyl groups and Si-bondedhydrogen atoms, which contains on average 1.8 vinyldimethylsiloxy and1.0 hydridomethylsiloxy groups per molecule and has a viscosity of 72mm²/s at 25° C.

c) Component B-3

The following siloxanes are equilibrated at 145° C. with 75 ppm ofPNCl₂:

360 g of a trimethylsiloxy-terminated dimethylpolysiloxane having aviscosity of 5000 mm²/s at 25° C., 1240 g of a vinyl-terminateddimethylpolysiloxane with an iodine number of 22 and

80 g of a trimethylsiloxy-terminated equilibrate comprising equimolaramounts of dimethylsiloxy and hydridomethylsiloxy units, with aviscosity of 70 mm²/s at 25° C.

Working up gives a polymer with Si-bonded vinyl groups and Si-bondedhydrogen atoms, which contains on average 1.9 vinyldimethylsiloxy and1.0 hydridomethylsiloxy groups per molecule and has a viscosity of 47mm²/s at 25° C.

d) Component B-4

The preparation procedure for component B-3 is repeated but with thechange that now, instead of 360 g of the siloxane with a viscosity of5000 mm²/s at 25° C., 1500 g of a siloxane with a viscosity of 10,000mm²/s at 25° C. are employed.

The product, when freed from volatile constituents, has a viscosity of108 mm²/s at 25° C. and contains on average 1.8 vinyldimethylsiloxy and1.0 hydridomethylsiloxy groups per molecule.

EXAMPLE 1

A solution of 252 g of an α,ωdivinyldimethylpolysiloxane having about160 siloxy units per chain in 380 ml of cyclohexane is activated with 10mg of platinum in the form of aplatinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, theso-called Karstedt catalyst, corresponding in the text below to thecatalyst as prepared in accordance with U.S. Pat. No. 3,775,452, and isheated to 86° C. until gentle boiling at reflux ensues. Over a period of2.5 hours a total of 322 g of component B-1, whose preparation isdescribed above, are metered in at a uniform rate.

The clear, homogeneous product solution is freed gives 551 g of a clear,highly viscous oil of 11,300 mPa.s at 25° C. and an iodine number of 7.The polymer contains, per kg, 275 mmol of vinyl groups in the form ofdimethylvinylsiloxy units; Si-bonded hydrogen can no longer be detected.The polymer has an average molecular weight, determined by means of gelpermeation chromatography, of 33,000 and contains on average 9CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

EXAMPLE 2

106 g of an equilibrate comprising dimethylsiloxy andvinyldimethylsiloxy units, with an iodine number of 22, are catalyzedwith 3 mg of platinum in the form of a Karstedt catalyst and heated to120° C. Over the course of 2.5 hours 200 g of component B-1, whosepreparation is described above, are metered in at a uniform rate and thereaction mixture is freed from volatile constituents in vacuo at up to140° C. This gives a polyaddition product having a viscosity of 320mm²/s at 25° C. and an iodine number of 13, corresponding to a vinylcontent of 510 mmol of vinyl groups per kg. It contains no detectableSi-bonded hydrogen. The polymer has an average molecular weight,determined by means of gel permeation chromatography, of 8000 andcontains on average 4 CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

EXAMPLE 3

Example 2 is repeated adding only half the amount of component B-1.Analogous working up gives a polymer having a viscosity of 79 mm²/s at25° C. and an iodine number of 15. The polymer has an average molecularweight, determined by means of gel permeation chromatography, of 4200and contains on average 2.5 CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

Comparison Experiment 1

Component B-1 is activated, without the addition of a component A, at23° C. with Karstedt catalyst so that the platinum concentration is 10ppm. The stirred solution slowly heats to 31° C. and becomesprogressively more viscous. After a few minutes the silicone oil hasgelled and is no longer flowable. The solid polyaddition product isinsoluble and is no longer suitable for preparing heat-crosslinkingcompositions.

Comparison Experiment 2

Component B-2, whose preparation is described above, is activated withKarstedt catalyst as described in Comparison Experiment 1. The viscosityrises steadily until, again, an insoluble gel is obtained.

EXAMPLE 4

75 g of an α,ω-divinyldimethylpolysiloxane having a viscosity of 100,000mPa.s at 25° C. (contains 2.0 meq. of vinyl) are diluted in 175 g oftoluene, and, as in Example 2, the same amount of the platinum catalystis added. At 102° C. over the course of about 2 hours a total of 250 gof a 30% strength solution of component B-3, whose preparation isdescribed above, are metered in at constant rate, the overall amount ofSi-bonded hydrogen being 25 meq., i.e. on average 25 molecules of B-3are added onto one molecule A as initially charged. After a further halfan hour at 102° C. the mixture is cooled. The polymer solution has aviscosity of 240 mm²/s at 25° C. and contains 49 mmol of vinyl groupsper kg. The polymer has an average molecular weight, determined by meansof gel permeation chromatography, of 120,000 and contains on average 20CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

EXAMPLE 5

Half of the polymer solution of the product from Example 4 (250 g) isagain heated to 102° C. and component B-3 as a 30% strength solution(215 g) is again metered in over the course of 2 hours, so that theoverall amount of the additionally added Si-bonded hydrogen is 21.5 meq.Identical subsequent reaction gives, ultimately, a polymer solutionhaving a viscosity of 914 mm²/s at 25° C. and a content of 68 mmol ofvinyl groups per kg. Overall, therefore, on average 68 molecules of B-3had been added onto the molecule as initially charged in Example 4. Thepolymer solution exhibits uniform flow behavior and no gel fractionswhatsoever. It can be diluted as desired with hydrocarbons to givehomogeneous solutions. The polymer has an average molecular weight,determined by means of gel permeation chromatography, of 200,000 andcontains on average 47 CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

EXAMPLE 6

264 g of the component B-4 whose preparation was described above aremixed homogeneously with 9.3 g of 1,3-divinyltetramethyldisiloxane,after which 1.5 mg of Pt in the form of the Karstedt catalyst are added.The reaction mixture is heated at 120° C. for about one hour. This givesa branched graft polymer having a viscosity of 280 mm²/s at 25° C. andan iodine number of 13.5. The polymer has an average molecular weight,determined by means of gel permeation chromatography, of 7400 andcontains on average 4 CH₂═CH(CH₃)₂SiO_(1/2) units per molecule.

Comparison Experiment 3

Example 6 is repeated without mixing in the1,3-divinyltetramethyldisiloxane. The mixture becomes very viscous whenheated and then turns into an insoluble gel.

Comparison Experiment 4

Instead of the component B-1 in Example 1 use is made of a vinyl-freebut otherwise identical version, i.e. a siloxane which contains onlytrimethylsiloxy end groups, and which is not in accordance with theinvention. Working up gives a polymer having a viscosity of 730 mm²/s at25° C., which according to the ¹H-NMR spectrum no longer has any vinylgroups.

EXAMPLE 7

The following constituents of a formulation for preparing releasecoatings are mixed in succession:

21.9 g of polymer from Example 6

55 mg of 1-ethynylcyclohexanol

1.4 g of crosslinker*

220 mg of Pt catalyst** (=2.2 mg of platinum)

* Equilibrate comprising hydridomethylsiloxy and trimethylsiloxy units,having a viscosity of 18 mm²/s at 25° C.

** Solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxanecomplex in linear α,ω-divinyldimethylpolysiloxane, having a platinumcontent of 1%.

The mixture has a gel time of about 70 hours at 25° C. A coating with athickness of about 4 μm is applied to supercalendered paper using aglass rod and is cured at 90° C. in a convection oven.

Stroke test Substrate adhesion 3 seconds' curing time 1-2 1-2 5 seconds'curing time 1 1

1=best rating, 6=worst rating

After 5 seconds at 90° C. a coating absolutely free from stroke marksand with excellent substrate adhesion was obtained. Isothermal curingunder static conditions was measured by means of DSC (DifferentialScanning Calorimetry) at 80° C.: exothermic peak after 6.3 minutes witha total of 44 J/g heat output.

What is claimed is:
 1. A polymeric organosilicon compound which containshydrocarbon radicals having at least one terminal aliphaticcarbon-carbon double bond, comprising the reaction product of (A)terminally unsaturated compounds selected from the group consisting of(A1) one or more polymeric organosilicon first reactant(s) selected fromthe group consisting of R¹ _(a)R_(3−a)Si(R¹RSi)_(n)(R₂Si)_(m)SiR¹_(a)R_(3−a)  (I), R¹ _(a)R_(3−a)SiO(R¹RSiO)_(n)(R₂SiO)_(m)SiR¹_(a)R_(3−a)  (II), and R¹_(a)R_(3−a)Si—R²—(R¹RSi—R²—)_(n)(R₂Si—R²—)_(m)SiR¹ _(a)R_(3−a)  (III),where R and R¹ are as defined below, R² is a divalent hydrocarbonradical having 2 to 8 carbon atoms, a is identical or different at eachoccurrence and is 0 or 1, n is 0, 1, 2, 3 or 4, and m is 0 or an integerfrom 1 to 1500, with the proviso that said polymeric organosilicon firstreactant(s) contain at least one terminal radical R¹ per molecule, (A2)one or more organic compounds of the formula Y(CH═CH₂)_(x)  (IV) where Yis a mono-, di-, tri- or tetravalent hydrocarbon radical having 1 to 28carbon atoms, which can be interrupted by one or more oxygen, silicon,boron or titanium atoms or contains one or more —CO₂— groups, where x is1, 2, 3 or 4, and mixtures of (A1) and (A2) with (B) oligomeric orpolymeric organosilicon second reactant(s) which comprise (B1) units ofthe general formula R¹R₂SiO_(1/2), (B2) at least one unit selected fromthe group consisting of the general formulae HRSiO and HSiO_(3/2), and(B3) optionally one or more units of the general formula R₂SiO, where Ris identical or different at each occurrence and is a monovalent,substituted or unsubstituted hydrocarbon radical having 1 to 18 carbonatoms per radical, which is free from aliphatic carbon-carbon doublebonds, R¹ is identical or different at each occurrence and is amonovalent hydrocarbon radical having 2 to 18 carbon atoms per radical,which contains at least one terminal aliphatic carbon-carbon doublebond, with the proviso that the sum of the units HRSiO and R¹R₂SiO_(1/2)is on average greater than 2.0 if (B) contains no units HSiO_(3/2), andthe number of radicals R¹ in said second reactant(s) is on averagegreater than the number of Si-bonded hydrogen atoms in said secondreactant(s), in the presence of (C) catalysts which promote the additionof Si-bonded hydrogen onto an aliphatic double bond, the ratio ofaliphatic double bonds in components (A) and (B) to Si-bonded hydrogensin component (B) being from 1.5 to 10, with the proviso that thepolymeric organosilicon compound contain on average more than twohydrocarbon radicals having at least one terminal aliphaticcarbon-carbon double bond.
 2. A polymeric organosilicon compound asclaimed in claim 1, wherein as component (A) organopolysiloxanes of thegeneral formula R¹ _(a)R_(3−a)SiO(R¹RSiO)_(n)(R₂SiO)_(m)SiR¹_(a)R_(3−a)  (II) where a is 1 and n is 0, 1 or 2, are employed.
 3. Apolymeric organosilicon compound as claimed in claim 1, wherein ascomponent (A) organic compounds (A2) are employed.
 4. A polymericorganosilicon compound as claimed in claim 1, wherein as component (B)organopolysiloxanes of the general formula R¹_(b)R_(3−b)SiO(R¹RSiO)_(o)(HRSiO)_(p)(R₂SiO)_(q)SiR¹ _(b)R_(3−b)  (VI)are employed, where b is identical or different at each occurrence andis 0 or 1, o is 0, 1, 2 or 3, p is 1, 2 or 3, and q is 0 or an integerfrom 1 to 100, with the proviso that the sum b+p is on average greaterthan 2.0, and the number of radicals R¹ is on average greater than thenumber of Si-bonded hydrogen atoms.
 5. A polymeric organosiliconcompound as claimed in claim 4, wherein b is 1, o is 0 or 1 and p is 1or 2, with the proviso that the sum b+p is on average greater than 2.0and the number of radicals R¹ is on average greater than the number ofSi-bonded hydrogen atoms.
 6. A process for preparing a polymericorganosilicon compound as claimed in claim 1, which comprises reacting(A) terminally unsaturated compounds selected from the group consistingof (A1) one or more polymeric organosilicon first reactant(s) selectedfrom the group consisting of R¹ _(a)R_(3−a)Si(R¹RSi)_(n)(R₂Si)_(m)SiR¹_(a)R_(3−a)  (I), R¹ _(a)R_(3−a)SiO(R¹RSiO)_(n)(R₂SiO)_(m)SiR¹_(a)R_(3−a)  (II), and R¹_(a)R_(3−a)Si—R²—(R¹RSi—R²—)_(n)(R₂Si—R²—)_(m)SiR¹ _(a)R_(3−a)  (III),where R and R¹ are as defined below, R² is a divalent hydrocarbonradical having 2 to 8 carbon atoms, a is identical or different at eachoccurrence and is 0 or 1, n is 0, 1, 2, 3 or 4, and m is 0 or an integerfrom 1 to 1500, with the proviso that said polymeric organosilicon firstreactant(s) contain at least one terminal radical R¹ per molecule, (A2)one or more organic compounds of the formula Y(CH═CH₂)_(x)  (IV) where Yis a mono-, di-, tri- or tetravalent hydrocarbon radical having 1 to 28carbon atoms, which can be interrupted by one or more oxygen, silicon,boron or titanium atoms or contains one or more —CO₂— groups, where x is1, 2, 3 or 4, and mixtures of (A1) and (A2) with (B) oligomeric orpolymeric organosilicon second reactant(s) which comprise (B1) units ofthe general formula R¹R₂SiO_(1/2), (B2) at least one unit selected fromthe group consisting of the general formulae HRSiO and HSiO_(3/2), and(B3) optionally one or more units of the general formula R₂SiO, where Ris identical or different at each occurrence and is a monovalent,substituted or unsubstituted hydrocarbon radical having 1 to 18 carbonatoms per radical, which is free from aliphatic carbon-carbon doublebonds, R¹ is identical or different at each occurrence and is amonovalent hydrocarbon radical having 2 to 18 carbon atoms per radical,which contains at least one terminal aliphatic carbon-carbon doublebond, with the proviso that the sum of the units HRSiO and R¹R₂SiO_(1/2)is on average greater than 2.0 if (B) contains no units HSiO_(3/2), andthe number of radicals R¹ in said second reactant(s) is on averagegreater than the number of Si-bonded hydrogen atoms in said secondreactant(s), in the presence of (C) catalysts which promote the additionof Si-bonded hydrogen onto an aliphatic double bond, the ratio ofaliphatic double bonds in components (A) and (B) to Si-bonded hydrogensin component (B) being from 1.5 to 10, with the proviso that thepolymeric organosilicon compound contain on average more than twohydrocarbon radicals having at least one terminal aliphaticcarbon-carbon double bond.
 7. A crosslinkable composition comprising (1)a polymeric organosilicon compound as claimed in claim 1, (2)organosilicon compounds containing Si-bonded hydrogen atoms, (3)catalysts which promote the addition of Si-bonded hydrogen ontoaliphatic multiple bond and optionally, (4) agents which retard theaddition of Si-bonded hydrogen onto aliphatic multiple bond at roomtemperature.
 8. A crosslinkable composition comprising (1) a polymericorganosilicon compound as claimed in claim 2, (2) organosiliconcompounds containing Si-bonded hydrogen atoms, (3) catalysts whichpromote the addition of Si-bonded hydrogen onto aliphatic multiple bondand optionally, (4) agents which retard the addition of Si-bondedhydrogen onto aliphatic multiple bond at room temperature.
 9. Acrosslinkable composition comprising (1) a polymeric organosiliconcompound as claimed in claim 3, (2) organosilicon compounds containingSi-bonded hydrogen atoms, (3) catalysts which promote the addition ofSi-bonded hydrogen onto aliphatic multiple bond and optionally, (4)agents which retard the addition of Si-bonded hydrogen onto aliphaticmultiple bond at room temperature.
 10. A crosslinkable compositioncomprising (1) a polymeric organosilicon compound as claimed in claim 4,(2) organosilicon compounds containing Si-bonded hydrogen atoms, (3)catalysts which promote the addition of Si-bonded hydrogen ontoaliphatic multiple bond and optionally, (4) agents which retard theaddition of Si-bonded hydrogen onto aliphatic multiple bond at roomtemperature.
 11. A crosslinkable composition comprising (1) a polymericorganosilicon compound as claimed in claim 5, (2) organosiliconcompounds containing Si-bonded hydrogen atoms, (3) catalysts whichpromote the addition of Si-bonded hydrogen onto aliphatic multiple bondand optionally, (4) agents which retard the addition of Si-bondedhydrogen onto aliphatic multiple bond at room temperature.
 12. A processfor preparing coatings which repel tacky substances, comprising applyinga crosslinkable composition according to claim 7 to a substrate andcrosslinking said crosslinkable composition.
 13. A process for preparingcoatings which repel tacky substances, comprising applying acrosslinkable composition according to claim 8 to a substrate andcrosslinking said crosslinkable composition.
 14. A process for preparingcoatings which repel tacky substances, comprising applying acrosslinkable composition according to claim 9 to a substrate andcrosslinking said crosslinkable composition.
 15. A process for preparingcoatings which repel tacky substances, comprising applying acrosslinkable composition according to claim 10 to a substrate andcrosslinking said crosslinkable composition.
 16. A process for preparingcoatings which repel tacky substances, comprising applying acrosslinkable composition according to claim 11 to a substrate andcrosslinking said crosslinkable composition.